Comparison of Twin Block appliance and Herbst appliance in the treatment of Class II malocclusion among children: a meta-analysis

Abstract

Background Our meta-analysis aimed to evaluate the efficacy of applying Herbst and Twin Block appliances in the treatment of Class II malocclusion among children. Methods Databases, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), China VIP Database (VIP), and Wanfang were thoroughly searched from inception to August 9, 2023. The outcomes included skeletal, dental, and soft tissue changes. The weighted mean difference (WMD) was used as the effect indicator, and the effect size was expressed with a 95% confidence interval (CI). The heterogeneity of each outcome effect size was tested, and the heterogeneity statistic I2 ≥ 50% was analyzed by the random-effect model, otherwise, the fixed-effect model was conducted. Sensitivity analysis was performed. Results A total of 12 studies involving 574 patients were included in this meta-analysis. Herbst appliance had a statistically significant increase in mandibular body length (WMD: 1.44, 95% CI: 0.93 to 1.96, P < 0.001) compared with the Twin Block appliance. More increases in angle and distance of L1 to mandibular plane (MP) were found in the Herbst appliance compared with the Twin Block appliance. Significant and greater improvements in molar relationship (WMD: 0.79, 95% CI: 0.28 to 1.29, P = 0.002), posterior facial height (WMD: -1.23, 95% CI: -2.08 to -0.38, P = 0.005), convexity angle (WMD: -1.89, 95% CI: -3.12 to -0.66, P = 0.003), and Sella-Nasion plane angle (U1 to SN) (WMD: 3.34, 95% CI: 2.25 to 4.43, P < 0.001) were achieved in the Twin Block appliance. Herbst and Twin Block appliances produced similar effects in the skeletal and dentoalveolar changes including Sella-Nasion-point A (SNA), Sella-Nasion-point B, point A-Nasion-point B (ANB), overjet, and overbite. Conclusion As the findings revealed both Herbst and Twin Block appliances contributed successfully to the correction of Class II malocclusion. Compared with the Twin Block appliance, the Herbst appliance may have more advantages in mandibular bone movement. Twin Block therapy resulted in more improvement in the aesthetics of the face.

Evaluating the Effects of Carriere Motion Appliance and Twin Block Appliances in Class II Correction—A Retrospective Study

“…Various treatment modalities are available for Class II malocclusion correction, depending on the underlying cause and whether it involves a skeletal or dentoalveolar discrepancy [3,4]. Skeletal correction can be accomplished by using fixed appliances such as Forsus [5] or Herbst [6], removable functional appliances such as Twin Block (TB) [7], or the mandibular advancement appliance of Invisalign [8]. The TB appliance [7,9] induces significant skeletal changes, including mandibular advancement and posterior repositioning of the maxilla in the sagittal plane and an enlargement of the lower facial height in the vertical plane.…”

“…Nevertheless, a significant loss of anchorage was observed in patients treated with TB, including the forward movement of the incisors [10]. In addition, the use of the TB appliance may cause changes in the soft tissue, such as an improvement in profile convexity [6,7].…”